Square Shoulders??

[cZm]

Hi all
Silly question here but hopefully someone can help. Its a bit hard to explain.
I just bought some new TOYO Proxies, 225/35/18's (on 8J's) and it just seems like the side walls are not 35's and very bulbous looking. The shoulders look very rounded and not square - if that makes sense.

I am assuming it is all down to make of tyre, some are more squarer than others, do you think that is the case and if so what should I be look at with nice square shoulders.
I hope that makes sense.